TEST TUBE DETECTIVE
What is a property?
What is a physical property?
What is a chemical property?
Problem: What are some chemical properties of matter?
Using these properties what is the unknown sample?
Materials: 3 test tubes, test tube rack, magnifier, 2 small
beakers, 2 eye droppers, vinegar, water, iodine, baking
soda, baking powder, baby powder, cornstarch and an
unknown
Procedure:
1. As you get each type of solid, use a magnifier and observe the shape, rub a little between your fingers and
smell it. Write down you observations
2. Label three test tubes; "vinegar", "water", and "iodine".
3. Put 1 /2 mL of baking soda into each test tube.
4. Put a dropper full of vinegar, water, and iodine into the labeled test tube. 5. Make your observations.
6. Rinse out the test tubes with water.
7. Repeat steps 2 through 5 using baking powder, cornstarch, baby powder, and unknown.
Observations:
Substance
Physical properties Chemical properties
with vinegar
Chemical properties Chemical properties
with water
with iodine
baking soda
baking powder
cornstarch
baby powder
unknown
Conclusion:
1. What physical properties did you observe?
2. What chemical properties did you observe?
3. Which combinations were alike? In what ways?
4. What is the identity of your unknown?
5. What properties helped you decide?
6. How did you use the properties to identify the unknown substance?
7. You discovered that iodine and cornstarch have a distinct reaction that is indicated by a dramatic
color change. What happened when you mixed the iodine with the baking powder?
8. What happened when you mixed the vinegar with the baking powder? What else reacted this way?
9. Baking powder is a mixture. What do you think might be in baking powder?